diff --git a/libpsk/include/libpsk/codec/trx_device_base.hpp b/libpsk/include/libpsk/codec/trx_device_base.hpp
index 4967908..d9a886c 100644
--- a/libpsk/include/libpsk/codec/trx_device_base.hpp
+++ b/libpsk/include/libpsk/codec/trx_device_base.hpp
@@ -182,7 +182,7 @@ class trx_device_base	//Add noncopyable
 	trx_device_base& operator=(const trx_device_base&) = delete;
 	static constexpr auto MAX_CODECS = 4;
 	static constexpr auto FFT_UPDATE_TIME_MS = 250; //FFT update time in ms
-	static const auto TX_SAMPLE_RATE = 32000;
+	static const auto TX_SAMPLE_RATE = 8000;
 	static const auto RX_SAMPLE_RATE = 8000;
 public:
 	//Os specific locker
diff --git a/libpsk/include/libpsk/port/isix/stm32adac_device.hpp b/libpsk/include/libpsk/port/isix/stm32adac_device.hpp
index 3f6caed..8020e10 100644
--- a/libpsk/include/libpsk/port/isix/stm32adac_device.hpp
+++ b/libpsk/include/libpsk/port/isix/stm32adac_device.hpp
@@ -22,17 +22,33 @@
 #include <board/adc_audio.hpp>
 #include <board/dac_audio.hpp>
 #include <isix.h>
+#include <foundation/dbglog.h>
 /* ------------------------------------------------------------------ */
 namespace ham {
 namespace psk {
 /* ------------------------------------------------------------------ */ 
 //STM32 AD/AC device
 class stm32adac_device : public trx_device_base, isix::task_base {
+	static constexpr auto THREAD_STACK_SIZE = 1024;
+	static constexpr auto THREAD_PRIORITY = 2;
 public:
 	static constexpr auto err_success = 0;
 	//! Constructor
 	stm32adac_device( handler_t evt_callback ) 
 		: trx_device_base( evt_callback ) {
+#if 0
+		//FIXME: Testonly sintab
+		    static constexpr auto fo = 1000;
+			static constexpr auto calc = 32767;
+			static constexpr float pi = 4 * std::atan(1);
+			for( int n = 0; n < 256; ++n ) {
+				m_tbuf[n] = calc + calc * std::sin( float(fo) * ( 2.0f * pi ) * (float)n / float(8000) );
+				//m_buf[n] = (n*65535)/ns;
+				//m_buf[n] = (n%2)?65535:0;
+				dbprintf("V=%i", (int)m_tbuf[n] - (int)calc );
+			}
+#endif
+			start_thread( THREAD_STACK_SIZE, THREAD_PRIORITY );
 	}
 	//! Destructor
 	virtual ~stm32adac_device() {
@@ -72,7 +88,9 @@ private:
 	isix::semaphore m_spectrum { 1, 1 };							//! Spectrum lock
 	isix::semaphore m_busy { 1, 1 };								//! Busy notificator
 	isix::semaphore m_start { 0, 1 };								//! Start thread
-	int m_thread_status {};											//! Thread error code
+	volatile int m_thread_status {};								//! Thread error code
+	volatile bool m_thread_cont { false };							//! Break main loop
+	//uint16_t m_tbuf[sample_size];									//! Test buffer
 };
 /* ------------------------------------------------------------------ */
 }
diff --git a/libpsk/src/port/isix/st32adac_device.cpp b/libpsk/src/port/isix/st32adac_device.cpp
index 6af79ec..0a44a1f 100644
--- a/libpsk/src/port/isix/st32adac_device.cpp
+++ b/libpsk/src/port/isix/st32adac_device.cpp
@@ -16,7 +16,7 @@
  * =====================================================================================
  */
 #include "libpsk/port/isix/stm32adac_device.hpp"
-
+#include <foundation/dbglog.h>
 /* ------------------------------------------------------------------ */
 namespace ham {
 namespace psk {
@@ -66,9 +66,11 @@ int stm32adac_device::setup_sound_hardware( trx_device_base::mode m )
 		}
 		const int ret = enable_hw_rx();
 		if( ret != 0 ) return ret;
+		dbprintf("Do receive processing");
 	}
 	if( m == trx_device_base::mode::transmit && get_mode()!=trx_device_base::mode::transmit )
 	{
+		dbprintf("Do transmit processing");
 		if( get_mode()==trx_device_base::mode::on )
 		{
 			const int ret = disable_hw_rx();
@@ -81,12 +83,16 @@ int stm32adac_device::setup_sound_hardware( trx_device_base::mode m )
 	if( get_mode()!=trx_device_base::mode::off && m == trx_device_base::mode::off )
 	{
 		//Disable and wait for stop
+		m_thread_cont = false;
 		join();
+		dbprintf("Thread exited - terminate");
 		return m_thread_status;
 	}
 	else if( get_mode()==trx_device_base::mode::off && m != trx_device_base::mode::off  )
 	{
 		//! Restart the thread again
+		dbprintf("Thread wakeup request");
+		m_thread_cont = true;
 		return  m_start.signal();
 	}
 	return err_success;
@@ -102,10 +108,18 @@ void stm32adac_device::main()
 		m_thread_status = m_busy.wait( isix::ISIX_TIME_INFINITE );
 		if( m_thread_status < 0 ) break;
 		int errcode = 0;
-		for(;m_start.getval()>0 && !errcode ;) {
+		dbprintf("Start procesing PSK");
+		for(; m_thread_cont && !errcode ;) {
+			lock( trx_device_base::lock_object );
 			if     ( get_mode()==trx_device_base::mode::on ) 	   errcode = receive_thread();
 			else if( get_mode()==trx_device_base::mode::transmit ) errcode = transmit_thread();
+			else {
+				dbprintf("Unknown mode %i!", get_mode() );
+				break;
+			}
+			unlock( trx_device_base::lock_object );
 		}
+		dbprintf("Stop procesing PSK reason getval: %i error: %i", m_start.getval(), errcode );
 		if( get_mode()==trx_device_base::mode::on ) {
 			//Disable sound receive
 			set_mode_off();
@@ -130,9 +144,8 @@ int stm32adac_device::receive_thread()
 	if( ptr == nullptr ) {
 		return m_adc_audio.errno();
 	}
-	lock( trx_device_base::lock_object );
 	adc_process( ptr, sample_size );
-	unlock( trx_device_base::lock_object );
+	//dbprintf("RX process ptr %p", ptr );
 	return m_adc_audio.commit_buffer( reinterpret_cast<uint16_t*>(ptr) );
 }
 /* ------------------------------------------------------------------ */ 
@@ -143,9 +156,14 @@ int stm32adac_device::transmit_thread()
 	if( !buf ) {
 		return m_dac_audio.errno();
 	}
-	lock( trx_device_base::lock_object );
 	auto status = dac_process( reinterpret_cast<int16_t*>(buf), sample_size );
-	unlock( trx_device_base::lock_object );
+	if( status == 0 ) {
+		for( size_t i = 0; i < sample_size; ++i ) {
+			reinterpret_cast<uint16_t*>(buf)[i] =  int( reinterpret_cast<int16_t*>(buf)[i] ) + 32767;
+		}
+	}
+//	memcpy( buf, m_tbuf, sizeof m_tbuf );
+	//dbprintf("TX process ptr %p", buf );
 	auto cstatus = m_dac_audio.commit_buffer( buf );
 	if( cstatus) return cstatus;
 	if( status) return status;